Using the MINOS Linux Cluster

MINOS has a Linux cluster that consists of 25 nodes each with two 3GHz
CPUs and 4 Gbytes of memory. The cluster is designed for
interactive use such as code development, debugging,
running ROOT sessions. If you want to run long batch
jobs on lots of data then you should be using the
condor or
lsf batch systems.

Nodes Names

The node names are minos01 - minos25.

Getting an account

Logging in

There are 25 nodes in the cluster. We hope to eventually have some
load balancing software that allows you to login to an
alias and be transferred to the least loaded
machine. Unfortunately we have been unable to make this
work at the present time. So users will have to look at
the load and choose a machine that is least busy. You can
look at the
Ganglia Monitoring(cluster only)
to see the load on the nodes. As always you should use ssh to login.

Home areas

Your home area is your FNALU AFS home area. So any work you do on
the cluster can also be accessed from the FNALU
interactive and batch nodes as well as your desktop if
you have the AFS client installed.

MINOS Offline Software

The MINOS offline software ia available via AFS. There are
instructions available for setting up the FNAL
base release.

Data disks

Each machine has a 250 GBytes disk as a local scratch disk. This is
mounted as /local/scratchxx where
xx=01,02,..,12. If you setup minossoft then
$SCRATCH will point to this disk on any of the nodes. These disks are designed for
temporary data storage and will be purged
monthly. Please create a directory for yourself.
All the existing AFS data space is available and is located at
/afs/fnal.gov/files/data/minos. An environmental symbol
$MINOS_DATA is available if you have setup minossoft. We
will be adding more AFS space shortly.

Data access

All nodes have access to /pnfs/minos. Instructions for
accessing data are available here. Data access via SAM
will be coming soon. Watch this space.

Interactive vs. Batch use

These nodes are for general MINOS use, both for development of code
and analysis processing. Heavy duty processing should be done using
either the
condor or
lsf
batch systems to ensure a fair share distribution of the resources.
Interactive use should be restricted primarily to development efforts
(e.g. compiling and running under the debugger) and very short jobs.
Running multiple interactive jobs on one or more machines is unacceptable
unless pre-approved.

Users should try to
avoid nodes that have predefined purposes as described
here.